Solar FAQS


1. How does solar technology work?

A solar photovoltaic (PV) module is an array of cells containing semiconductor materials that convert solar radiation into direct current electricity. If a solar PV system is connected to the power grid, any excess electricity it produces is fed into the grid. When the sun isn't shining, a PV system cannot produce electricity; however, the grid will supply additional electricity that is needed to the connected system, as necessary. Click here to learn more about how solar technology works.


2. How much solar power potential exists in Rhode Island?

Solar energy resources are modest in Rhode Island compared to other regions of the country. Even so, total solar power potential in Rhode Island easily exceeds the entire electric needs of the state. This is because solar power potential is limited only by available land and roof area. Rhode Island’s State Energy Plan suggests the state could develop over 1,800 MW of solar energy by 2035.


3. How many solar installations are there in Rhode Island?

As of December 2016, the Ocean State had an installed solar PV capacity of approximately 37 MW, with 2,105 known installations.


4. How much of Rhode Island's electricity needs does solar energy provide?

Rhode Island consumes approximately 7,700 GWh of electricity each year. Assuming a 13% capacity factor, Rhode Island solar installations generate a total of about 42,000 MWh per year. Therefore, in-state solar installations currently supply roughly 0.5% of Rhode Island’s electricity needs.


5. Reduce energy use through energy efficiency

Because the sun shines intermittently, solar installations don’t produce power at their maximum capacity all of the time. A capacity factor is a ratio or percentage that represents a solar project’s actual energy output versus its maximum potential energy output. The value is typically reported as an annual figure, with the maximum potential energy output assuming the solar installation could operate at its nameplate capacity continuously throughout the year. Solar installations located in areas with more solar resources have higher capacity factors. In Rhode Island, solar systems typically see capacity factors around 13%.


6. How many homes can be powered by a 1 MW solar installation?

A 1 MW solar system in Rhode Island can power approximately 190 homes annually, assuming a 13% capacity factor and an average household use of 500 kWh.


7. How much carbon dioxide does a solar installation offset?

An average residential rooftop solar PV system of 5 kW can offset approximately 2 metric tons of carbon dioxide annually, roughly equivalent to taking a half of a car off the road. A 1 MW solar installation can offset approximately 190 metric tons of carbon dioxide annually, roughly equivalent to taking 80 cars off the road. These calculations assume a 13% capacity factor, a New England carbon dioxide emissions rate of 730 lb/MWh, and annual emissions per car of 4.7 metric tons of carbon dioxide.

State of Rhode Island

Office of Energy Resources